No causative studies has ever shown artificial sweeteners causing weight gain.

没有任何研究表明人造甜味剂会导致体重增加。

However, in about 40% to 25% of the cases the causative genes are still unknown.

但是，有40％至25％病例的致病基因仍然未知。

Now there are two ways that we can use have as a causative verb.

我们用 have 作为词有两种方式。

Maybe you noticed this structure is called the causative.

也许你注意到这被称为。

Let's look at another causative verb — have.

我们来看看另一词 have。

Now you know the meanings of the three most common causative verbs.

现在你知道了三最常见的词的意思了。

There are more than 10 causative verbs in English.

英语中有 10 多词。

And it's the same with the causative verb 'have'.

词 have 也一样。

Let's look at the second way in which we can use have as a causative verb.

我们来看看把 have 作为词的第二种方式。

Last week we looked at the meanings of three common causative verbs.

上周我们学习了三常见词的意思。

Get is another causative verb and it means the same thing as have, but the pattern is different.

get 也是词，它的意思和 have 是一样的，只是形式不同。

This causative verb is used to say that we forced someone or something to do something.

这词被用来说我们强迫某人或某事做某事。

Again you only need to conjugate the causative verb.

同样地，你只需要改变词的形式。

There are lots of causative verbs and 'make', 'let' and 'have' are the most common ones.

词有很多，“make”、“let”和“have”是最常见的。

The tricky thing is the pattern they follow when they're causative verbs, and it's this.

棘手的是，当它们是词时，所遵循的模式是这样。

In Africa, we experience more than 140 outbreaks every year: viral outbreaks, bacterial outbreaks, or outbreaks of unknown causative agent.

在非洲，我们每年经历 140 多起疫情：病毒疫情、细菌疫情或未知病原体疫情。

There's the causative verb, then the person who does the action, and then the action.

首先是词，然后是做作的人，最后是作。

You will only use " have" and " get" in the passive causative.

您只会在被中用“have”和“get”。

Some are in the causative structure; some are not in the causative structure.

有些属于；有些不属于。

While adenovirus is a possible hypothesis, investigations are ongoing for the causative agent.

虽然腺病毒是一种可能的假设， 但正在对病原体进行调查。